wojeda

I have been trying to troubleshoot a problem that started to happen right after my cam and heads add-on (see sig). The car dies coming off cruising speed onto a stop. RPMS go down to 400 then it stumbles and stalls.
The same thing happens every time the A/C compressor kicks in at idle. Other that that it runs like a dream. Idles fine and it is scrary at WOT.

I put a new IAC and it did not helped. I got a new program from PCMforless where he upped the air intake at idle and it got better but still goes down to 450rpms. Half the time it recovers and the other half stalls.

Anyways, I put a FP gauge (the good one), on the rail and it was reading almost 60PSI!!! I am using a Aeromotive billet AFR. Before the cam it was set dead on 43PSI and it kept it. Now this. So I figure that now that I am pulling 14.5 Hg vs. the 20 stock, the regulator was not dropping properly. Is this a correct assumption?

I dropped the pressure to 45 with ignition on and vacuum off the AFR but it starts dropping rather fast and it settles at 30PSI. If I cycle the ignition goes back to 45 and starts to drop again. If I start the car the pressure goes up to 43PSI at idle and it keeps it and if reved, it goes up to close to 50PSI. Is my AFR screwed up? Do I have an injector leaking?

The injector leaking was the idea I got when the car after is hot it takes 5 cranking seconds to start. If it is cold it starts right away. I am way off here also?


Thanks for any input on this.

unTAmedLS1

omg I HAVE THE SAME EXACT PROBLEM EXACTLY. Thats exactly what happens and I have same mods. I have mods in sig wow thats freaky I hope someone knows the solution. Only now my car is running lean as hell and this only started about 1 week ago. I cant even drive it because it misfires and says im running real lean so I thought it was a bad injector and found one that didnt ohm out good. So I replaced it and its still doing the exact same thing. I have stock fuel system with 1 year old AC delco pump and fuel filter at the same time. God I hope someone knows cuz this is frustrating. Also I pulled all the plugs and the car is indeed running lean.

Z95m6

you need to drill out the IAC in the throttlebody. Mine would stumble and almost die when the ac was on when i first got my car together. I drilled it out and it cleared everything up. Do a search on it there are some threads on it. You need to do this mod if you have a cam.

turbo_Z

yep this procedure does help out quite a bit. the IAC motor cant keep up with the amount of air your car requires so drilling out this hole larger allows for more air flow so your IAC doestn work as hard. you could also crack the tb blades to get he same affect but then you arent getting all the idle air flowing thru the IAC passages and that can cause idle problems.

unTAmedLS1

Found out I also have a bad o2 so im gonna replace it today and see what happens.

wojeda

I will try the IAC procedure and see what happens. I am still searching for a good thread that shows how to do it, what size drill bit and so forth. So, if anyone has a link to one, I apreciate plug it here.

Also, any ideas on the fuel pressure issue?
Again, the first time I hooked up the gauge it had 60PSI. I reged it down to 45 but it does not keep it. It idles at 43 and revs at 50. Shut off the engine and it drops to 30. Any ideas?


unTAmedLS1: How did you find out about the O2? I am not setting any codes over here?